The separation is maintained by the fact that a person in New York cannot get the local newscast in Redwoods, California while a Seattle resident isn't able to get a West Palm Beach, Florida newspaper. There are limitations on time and space and broadcasting rights that prevent such a widely-spread level of information distribution.
But on the Internet the difference between continents is minuscule, so the separation between the coasts is minimal. A person can find out what is going on all across the country just by accessing the local newspaper or television station's website.
The information will be as complete as it is anywhere due to the proximity.
Which raises the question... if local news sources cover local stories in a more in-depth manner, why should network or national news exist? With the world getting smaller, information that one would only be able to get from a national news source is now available right from the local newspaper that has been covering the story for weeks. And unlike a national source, the local will have more follow-up stories and may have covered the story on a few different angles, giving a more complete understanding of the event.
E.W. Scripps Company put this idea to the test in Florida when it banded its several newspapers with its television station to present a news Web for Florida. Stories from each local source were placed together, with in-depth reporting from their beat writers. The site has had success with this formula resulting in increasing traffic at their site.
The idea was put into work on a much grander scale in Canada. The Canadian On-Line Explorer, or Canoe, banded together the major newspapers of each province and created the definitive "national" Canadian website. Smaller stories are covered by the local paper for the site, while stories of a larger scope, like the attempted secession of Quebec, are covered by all of the papers, each providing a local viewpoint on the story.
In theory, this seems like the perfect antidote for national news, removing the small 'big picture" story and replacing it with a series of stories profiling the entire scenario. When the camera pulls back from the one-story example though, the problems begin.
There are 50 states in America, each with hundreds of papers. Each has their 'big" stories and each deserves to be considered in the scope of national news. But how does the average, casual news watcher decide what to read with a myriad of choices before them? The national news sources handle this duty for us currently and do a decent job at duplicating our decisions.
The national news takes on the role of a clearinghouse for us, applying a different set of news values to the country's news, and providing us with 'the best of the best." Stories that affect the largest amount of people, or have serious consequences or provide helpful information will make the cut before an unusual story out of Tennessee. We will miss out on a lot of important stories, that will hopefully find their way to our papers, but overall we will be better informed by having more time to read, with less time spent searching.